Zengrui Wang – Medium

Apr 20

Binary Tree Threading & Morris In-order Traversal

I was doing a Leetcode question: Recover Binary Search Tree. In the follow-up, it asks if you can solve it with O(1) space complexity which turns out to use the Morris Inorder Traversal. It took me a while to understand why the algorithm works and I’d like to share my…

Binary Tree

4 min read

Feb 13, 2021

Excuse me, that’s MY SPOT!

Every Jack has his Jill. Every man can expect to have his partner. Recently, I did some interesting array-related interview questions. The problem description starts like this or similar: Given an array nums containing n numbers in the range [0, n] … and asks you to find duplicate/missing numbers. Here…

Algorithms

4 min read

Jun 29, 2020

Solving Tree-related Problems

A tree data structure can be defined recursively as a collection of nodes (starting at a root node), where each node is a data structure consisting of value, together with a list of references to nodes (the “children”), with the constraints that no reference is duplicated, and none points to…

Interview Questions

4 min read

Mar 18, 2019

RESTful, Resource-Oriented Architecture

I am currently reading the book “RESTful Web Service”, before this I have very limited knowledge about REST to the point that I even don’t know what do those four characters stand for. This article is a brief reading note from Chapter 1 to 4. REST(Representational State Transfer) is a…

Rest

5 min read

Apr 4, 2018

Sliding Window Technique

Sliding window technique is useful for solving problems in array or string, especially it is considered as a technique that could reduce the time complexity from O(n²) to O(n). There are two types of sliding window: Fixed window length k: the length of the window is fixed and it asks…

Programming

5 min read